SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '020d31368cff2e6740d097dbe07d3db79f10fc322fca552b8e2615de63fe857a' 
  AND token = 'cdg/Mp6WWogiQyj+19f7sMUgLBJNseggCUBDQYdfLtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}